In the assembly of laboratory test equipment, it is often necessary to connect a sample line into test equipment such as a valve, test instruments and the like. These are manufactured by many different makers, and, quite often, they are constructed in accordance with differing standards, or indeed, no particular standard whatsoever with regard to the size of the fittings. For instance, it is often necessary to connect lines as small as one sixteenth of an inch OD into a fitting which is perhaps as large as one quarter inch or even five sixteenths of an inch. Sometimes, it is necessary to connect fittings which differ only by one sixteenth of an inch. Even so, all such mismatched connections are difficult without regard to how different the respective measures of the misfit might be.
Typical laboratory test equipment including test instruments, valves and the like generally are manufactured with a common thread standard. However, there is no standard as to the diameter of the fittings. Sometimes it will be necessary to connect into a female internally tapped opening of a test instrument. At other times, the test instrument may incorporate a threaded male fitting. The present invention is an apparatus which cooperates with an internally tapped female fitting or an externally threaded male fitting. In particular, it enables connection of a misfitted arrangement. By misfitted. reference is made to connection of a tubing to a fitting where the tubing is different in size from the fitting. This is normally intended for use in laboratory and test instruments where typical sizes are in the range of about one sixteenth of an inch OD to not more than one-half inch. Within the range of these typical sizes, tubing which is typically formed of copper or some plastic material (e.g., polyethylene) with adequate wall thickness to provide suitable strength against the crushing force is used.
The present apparatus is further advantageous in that the equipment is assembled quite easily. It is assembled by threading members together into the fitting. They are assembled to it sequentially. This more readily permits one-handed assembly as opposed to requiring two wrenches held in two hands. While there are many components which require wrench tightening, they are, nevertheless, assembled at different times, and, therefore, they are conveniently assembled by the use of only a single wrench.
The term "fitting" which is used herein refers to a male or female fitting which is typically an input for a test instrument or larger instrument. By way of example and not limitation, it may be a multiport valve assembly, a chromatographic analyzer and so on.